bensallen / rbd

Go Library and CLI for Mapping/Unmapping Images with the Ceph Linux RBD client

Go RBD CLI

Golang based Ceph RBD image map, unmap, boot, and device list utility and library. No external dependencies outside of the Kernel's RBD sysfs interface.

$ rbd -h
rbd - Ceph RBD CLI

Usage:
  rbd [map|unmap|device|boot]

Subcommands:
  map      Map RBD Image
  unmap    Unmap RBD Image
  boot     Boot via RBD Image
  device   Manage RBD Devices

Flags:
  -h, --help      Diplay help.
  -n, --noop      No-op (don't actually perform action).
  -v, --verbose   Enable additional output.
  -V, --version   Displays the program version string.

map

$ rbd map -h
map - Map RBD Image

Usage:
  map

Flags:
      --id string          Specifies the username (without the 'client.' prefix)
  -i, --image string       Image to map
  -m, --monitor strings    Connect to one or more monitor addresses (192.168.0.1[:6789]). Multiple address are specified comma separated.
      --namespace string   Use a pre-defined image namespace within a pool
  -p, --pool string        Interact with the given pool.
      --read-only          Map the image read-only
      --secret string      Specifies the user authentication secret
      --snap string        Specifies a snapshot name

unmap

$ rbd unmap -h
unmap - Unmap RBD Image

Usage:
  unmap

Flags:
  -d, --devid int   RBD Device Index (default 0)
  -f, --force       Optional force argument will wait for running requests and then unmap the image

Boot

Tooling for booting from one or more RBD images.

1. Parses /proc/cmdline for RBD settings
2. Maps and mounts the image.
3. Mount's an overlayfs over the mountpoint if configured.
4. If argument is passed via the CLI, attempts to switch_root (typically requires being PID 1).

• See https://github.com/bensallen/rbd/blob/master/pkg/cmdline/cmdline.go#L50 for cmdline format (limited to JSON form currently)
• Currently requires passing the cephx secret via cmdline, which is not ideal.

$ rbd boot -h
boot - Boot via RBD image

Usage:
  boot

Flags:
  -c, --cmdline string       Path to kernel cmdline (default: /proc/cmdline) (default "/proc/cmdline")
  -m, --mkdir                Create the destination mount path if it doesn't exist
  -s, --switch-root string   Attempt to switch_root to root filesystem and execute provided init path

Device

$ rbd device -h
device - Manage RBD Devices

Usage:
  device [list|map|unmap]

Subcommands:
  list     List connected devices
  map      Map RBD Image
  unmap    Unmap RBD Image